Positive pressure clip



April 3, 1934. J. G. JACKSON POSITIVE PRESSURE CLIP Filed Dec. 15. 1950 INVENTOR 17,0277 Jae/YGO?? ATTORNEYS Patented Apr. 3, 1934 PATENT lorties POSITIVE PRESSURE CLIP John G. Jackson, Detroit, Mich., assignor to, Square D Company, Detroit, Mich., a corporation of Michigan Application December 15, 1930, Serial No. 502,565

10 Claims. V(Cl. 200-166) This invention relates generally to electrical contact jaws and more particularly to jaws of this type especially designed for use in connection with electrical apparatus for retaining fuses or switch blades in an electrical circuit.

Heretofore jaws employed in the construction of electrical apparatus have been objectionable in that after continued use, the spring contact fingers have atendency to lose their resiliency and accordingly increase the contact resistance between the same and the part with which they are used resulting in a loss of electrical energy.

The present invention contemplates the provision of auxiliary means for exerting a positive pressure upon the jaws tending to resist separation thereof upon insertion of a member therebetween or in other words tending to urge the jaw portions toward each other into firm engagement with the said member. Thus, it will be observed that the means aforesaid stabilizes or reinforces the jaws with the result that any tendency for the latter to lose their resiliency or clamping action, as previously stated, is reduced to a minimum. Moreover, by supplementiary 4pressure producing or reinforcing means, as previously stated, the jaws may be fashioned from copper without the danger of the jaw becoming distorted to the extent of losing its flexibility. The use of copper for forming the jaws is desirable not 'only' because the conductivity of copper is higher than bronze, brass and other more rigid materials, but also due to the fact that copper is less expensive than other available materials such asthose mentioned.

A further advantageous feature of this invention is to provide means of the type set forth above in the form of a metallic spring arranged to embrace the contacting portions of the jaw and with the latter adapted to be secured to a supporting member by a single fastening element which incidentally may be used to properly position the part engaged between the jaw portions relative to the latter.

With the foregoing as well as other objects in view, the invention resides in the peculiarconstruction of the jaw which will be made more Aapparent as this description proceeds, especially when considered in connection with the accom- -panying drawing, wherein:

Figure 1 is a side elevation of a clip embodying my invention and showing portions of a fuse and current carrying member associated therewith;

Figure 2 is an end elevation of the structure illustrated in Figure 1;

ing the inherent pressurel of the jaws with auxilvurging the same toward each other.

Figure 3 is a View similar to Figure 1 but showing a slight modification;

Figure 4 is an end elevation of the structure illustrated in Figure 3.

Referring now to the drawing, it will be noted that there is illustrated in Figure 1 a U-shaped jaw 10 having its base portion 12 clamped directly upon a suitable current carrying member 13 by means of the bolt 14 and nut 15, and having inturned fingers or contact portions 1'7 and 18 constructed to exert a pressure upon opposite sides of a member inserted therebetween so as to firmly clamp the member in position. The ngers 17 and 18 are spaced laterally from each other a distance substantially less than the width of the blade adapted to be inserted therebetween and the construction is such that the intimacy of the contact between the fingers and the blade is beneficially affected by the pressure which the fingers exert upon the blade. v

In order to provide an eflicient construction and at the same time to stabilize the clamping action of the spring fingers 17 and 18, I provide auxiliary means for exerting an inward pressure upon the opposed fingers tending to urge the same toward each other. Preferably this auxiliary means comprises a steel wire having portions 32 intermediate the ends looped around the fastening element 11 which also serves to secure the jaw to a suitable current carrying member. The ends of the looped portion 32 are adapted to cross each other as shown in Figure 2 and terminate in spaced fingers 36 adapted to engage the outer surfaces of the lingers 17 and 18 for urging the same toward each other.

The construction illustrated in Figures 3 and 4 comprises a jaw 3'7 substantially U-shaped in cross section with the base of the U clamped to a suitable current carrying member by means of a suitable fastener element 38 and the legs of the U having portions spaced above the basebent inwardly toward each other and terminating in jaw portions 39. Thejaw portions 39 are normally urged toward each other into contact with a part therebetween by means of a steel wire spring 4() having an intermediate portion looped around the fastener element 38. The ends of the looped portion extend outwardly beyond the jaw and terminate in resilient fingers 41 adapted to engage the outer surfaces of thejaw portions for It will be observed from Figures 3 and 4 that inward movement of the wire spring is prevented by engagement of the wire spring with the outer end portions of the jaw and outward movement of the wire spring is prevented by the fastener element 38 which also serves to limit the extent of insertion of the switch or fuse blade within the jaw portions. Thus, from the foregoing it will be observed that in each of the foregoing described constructions auxiliary means is provided for reinforcing and urging the contacting portions of the jaws toward each other so as to create the desired pressure contact between the jaw portions and the switch or fuse blade adapted to be inserted therebetween. It will also be apparent that in each of the above modifications the fastener element for attaching the jaws to a suitable current carrying member also serves to secure the metallic spring members in assembled. relation with the jaws and moreover, forms a stop for limiting the extent of engagement of the switch blades or fuse blades between the jaw portions.

Thus, from the foregoing it will be apparent that means is provided in each of the foregoing constructions for exerting a pressure upon the jaw portions to urge the same into contact with the terminal therebetween, thereby permitting the jaws to be fashioned from material of high electrical conductivity irrespective of the resilient qualities of the material.

What I claim as my invention is:

l. In combination, ajaw having a base and spaced resilient fingers for gripping a movable switch member therebetween, anchorage means for the jaw including a fastener element extending upwardly through the base, and means for urging the fingers toward one another to obtain the desired gripping action, including a wire having a substantially horizontal portion intermediate its ends looped about the fastener element, and having substantially horizontal portions bearing against the backs of the fingers aforesaid.

2. In combination, a jaw having a base and spaced resilient fingers for gripping a movable switch member therebetween, anchorage means for the jaw including a fastener element extending upwardly through the base, and means for urging the fingers toward one another to obtain the desired gripping action, including a wire having a substantially horizontal portion intermediate its ends looped about the fastener element, having upright portions rising from the looped portion in advance of the adjacent edges of the fingers and disposed substantially parallel thereto, and having horizontal portions projecting rearwardly from the upright portions across and bearing against the backs of the fingers aforesaid.

3. In combination, a jaw having a base and spaced resilient ngers for gripping a movable switch member therebetween, anchorage means for the jaw` and means for urging the fingers toward one another to obtain the desired gripping action, including a length of Wire having a substantially horizontal portion intermediate its ends enveloping a portion of the anchorage means, and having laterally spaced substantially horizontal portions disposed above and substantially parallel to the horizontal portion aforesaid and extending across and bearing against the backs of the fingers aforesaid.

4. A--clip having laterally spaced portions of current conducting material for gripping a portion-fof a fuse, said portions having longitudinal edges extending in the same general direction, and

reinforcing means for the clip including a single length of wire normally resisting separation of said portions but yieldable to permit such separation, said wire being bent substantially midway of its ends to provide a loop for attachment to suitable securing means for the clip and being bent adjacent its ends to provide arms that extend transversely of said portions.

5. A clip having a base,. and laterally spaced portions of sheet metal on the base for holding a portion of a fuse, said portions having longitudinal edges extending in the same general direction, anchorage means for the clip including a fastener element extending through the base, and reinforcing means for said clip including a single length of wire resisting separation of said portions but yieldable to permit such separation, said wire being bent to provide a loop for embracing the fastener element and being bent to provide arms that extend across and bear against the backs of said laterally spaced portions.

6. A clip having a pair of laterally spaced portions of sheet metal for holding a portion of a fuse, and means for urging said portions toward each other including a single length of spring wire bent to provide arms that extend transversely of said laterally spaced portions.

'7. A clip having a pair of laterally spaced portions of sheet metal for holding a portion of a fuse, and means for urging said portions toward each other including a single length of spring wire anchored intermediate of its ends, having portions extending longitudinally of said spaced portions and bent to provide arms that extend transversely and bear against the backs of said laterally spaced portions.

8. A clip having a pair of laterally spaced portions of sheetk metal for holding a portion of a fuse, and means for urging said portions toward each other including a single length of spring wire bent substantially midway of its ends to provide an attaching means, having portions extending longitudinally of said spaced portions and bent to provide arms that extend transversely and bear against the backs of said laterally spaced portions.

9. A clip having a pair of laterally spaced portions of sheet metal for holding a portion of a fuse, a fastening element for the clip, and means for urging said portions toward each other including a single length of spring Wire bent adjacent opposite ends thereof to provide arms that extend transversely of said laterally spaced portions and return-bent intermediate the bends aforesaid and embracing the fastening element for the clip.

10. In combination, a pair of spaced electric contact members of yieldable material for gripping engagement with a third contact member, a supporting member for said spaced members, a fastening element for the supporting member, and means for urging the spaced contact members toward one another so that they may grip the third Contact member aforesaid including a length of wire bent around the fastening element, and having portions extending longitudinally of said spaced contact members and bent adjacent their ends to provide arms that extend transversely of the spaced members intermediate of their ends.

JOHN G. JACKSON. 

